1. Field of the Invention
The present invention relates to an aluminum alloy flashlight and, more specifically, to a rear pushbutton type switch arrangement for flashlight.
2. Brief Description of the Related Art
FIGS. 1 and 2 show an aluminum alloy flashlight constructed according to the prior art (equivalent to U.S. Pat. No. 6,092,910). According to this design, the flashlight comprises an aluminum alloy barrel 10 holding a battery set (set of battery cells) a and a lamp assembly on the front side, a rotary rear cap 20 made of electrically conductive material and threaded into the rear end of the barrel 10, and a switch structure 30 mounted within the rotary rear cap 20 and partially extended out of the center through hole 201 of the rotary rear cap 20. The switch structure 30 comprises a spring set 301, a switch body 302, and a button 303. The spring set 301 comprises a metal spring 3011 and an electrically insulative spring holder 3012. The metal spring 3011 is mounted in the spring holder 3012 and extended out of the front side of the spring holder 3012. When received in the rotary rear cap 20, the front end of the metal spring 3011 is suspended out of the rotary rear cap 20 and stopped against one end (the negative terminal) of the battery set a. The switch body 302 comprises two lead out pins 3021 respectively connected to the metal spring 3011 and the inside wall of the rear rotary cap 20, and a switching rod 3022 coupled to the button 303. The button 303 has a press portion 3031 extended out of the rotary rear cap 20 through the center through hole 201. When the user pressed the press portion 3031, the switching rod 3022 is forced to switch on/off the switch structure 30, and to further turn on/off the flashlight.
This design of aluminum alloy flashlight is still not satisfactory in function. Because there is provided no positioning means to stop the spring set 301 in place, the spring set 301 tends to jump out of the rotary rear cap 20 when the rotary rear cap 20 disconnected from the barrel 10 for the replacement of the battery set a (see FIG. 4). Further, if the spring set 301 is not accurately set in position, the lead out pins 3021 may not be positively maintained in contact with the metal spring 3011 and the inside wall of the rotary rear cap 20, resulting in an error of contact (see FIG. 5).
Therefore, it is desirable to provide an aluminum alloy flashlight that eliminates the aforesaid drawbacks.
The present invention has been accomplished to provide a rear pushbutton type switch arrangement for flashlight, which eliminates the aforesaid drawbacks. It is the main object of the present invention to provide a rear pushbutton type switch arrangement for flashlight, which keeps the component parts of the switch structure firmly positioned inside the rotary rear cap after removal from the barrel of the flashlight for a replacement of the battery set. According to the present invention, the rear pushbutton type switch arrangement for flashlight comprises an aluminum alloy barrel holding a battery set and a lamp assembly, an electrically conducting rotary rear cap provided at a rear side of the barrel, and a switch structure mounted in the barrel and the rotary rear cap and partially extended out of the rotary rear cap for operation by the user to switch on/off the flashlight. The switch structure comprises an externally threaded, electrically conducting, hollow, cylindrical metal casing, the casing having a front end threaded into a rear end of the barrel, a rear end screwed up with the rotary rear cap, a small front axial hole and a big rear axial hole axially connected in a line, and an annular stop flange in front of the small front axial hole; a spring set mounted in the small front axial hole of the casing, the spring set comprising an electrically insulating spring holder mounted inside the casing and stopped behind the annular stop flange of the casing, and a metal spring isolated from the casing by the spring holder, the metal spring having a front end disposed in contact with the negative terminal of the battery set and a rear end; a switch body mounted in the big rear axial hole of the casing, the switch body comprising two pairs of first front lead out pins transversely arranged in parallel at a front side thereof and overlapped for connection to the rear end of the metal spring, a pair of second front lead out pin bent bilaterally backwards and maintained attached to the periphery of the switch body for contacting an inside wall of the rotary rear cap, and a rear switching rod; and a button coupled to the switching rod of the switch body and suspending in the rotary rear cap, the button having a press portion extended out of the rotary rear cap for operation by the user.